Top Energy has turned down what chief executive Russell Shaw described as "big sums" offered by Chinese interests to extract swamp kauri in the geothermal fields around Ngawha.
He said Top Energy's response was that the kauri was "too precious to sell".
Top Energy and Far North District Council are seeking a permanent protection order for the kauri lying buried within the geothermal zone. He said the Ngawha geothermal field had huge potential for tourism.
Meanwhile, the Northland Environmental Protection Society's (NEPS) challenge to laws allowing the exportation of ancient swamp kauri is being played out in the Auckland High Court this week.
The environmental group is seeking a judicial review before Justice Kit Toogood, challenging the Ministry for Primary Industries' interpretation of the act governing the export of native wood.
On the first day of what was expected to be a two-day hearing, the EPS' lawyer, Davey Salmon, argued there had been a "massive increase in exports" of raw kauri and the ministry had ignored provisions in the 1949 Forest Act prohibiting the export. Whole or sawn stumps or roots may be exported with a milling statement and export approval but sawn logs from a trunk may not. Mr Salmon has asked the court to define the law's "exact limits".
Conservationists say extracting swamp kauri destroys wetlands and threatens the habitat of rare species.
Last year the EPS and Northland MP Winston Peters both called for a moratorium on the export trade. Other opponents say exporters are circumventing the ban by labelling kauri slabs as table tops or superficially carving slabs and calling them artworks or Maori carvings.
One Far North businessman, who did not want to be named, said large trucks laden with logs "running up and down State Highway 1" were a common sight and some local people believe there is "wholesale" export of unaltered kauri from several areas in Northland.